In a major breakthrough, the Central Bureau of Investigation on Friday arrested sacked Rajasthan Minister Mahipal Maderna, who is a prime accused in the sensational case of abduction and probable murder of nurse Bhanwari Devi, who has been missing since the first week of September.

The arrest was made in Jodhpur hours after the CBI filed a charge-sheet against three other accused.

Parasram Bishnoi — brother of ruling Congress MLA from Luni, Malkhan Singh, another suspect in the case — was also arrested along with Mr. Maderna. Both of them were taken into custody after their prolonged interrogation at the CBI office in Jodhpur. The charge-sheet also named Mr. Maderna and an absconding suspect, Sahi Ram.

The arrest of Mr. Maderna and Mr. Bishnoi comes as a huge embarrassment for Chief Minister Ashok Gehlot, who was seen defending the Congress leaders, and advocating probity and morality in public life ever since the abduction case came to light. He was forced to drop Mr. Maderna from his Cabinet on October 16 after a case of abduction and murder was registered against him on a court direction.

The former State Water Resources Minister, 59, since suspended from the primary membership of Congress, had reportedly confessed to having had an “illicit relationship” with Ms. Devi after a compact disk showing the two in a compromising position was circulated here. However, he has denied any role in her disappearance during the questioning by the CBI.

Ms. Devi's husband Amar Chand has alleged that his 36-year-old wife was abducted at the behest of Mr. Maderna and his accomplices. He has expressed apprehension in his statements recorded by the CBI that his wife has been killed and her body destroyed.

In its charge-sheet filed against three accused — who are presently in judicial custody — before Metropolitan Magistrate Jagdish Jyani in Jodhpur on Friday, the CBI has named Mr. Maderna and stated that investigations are pending against him. It sought the court's permission for continuing the investigation in the case. who are presently in judicial custody – before Metropolitan Magistrate

The CBI, in its charge-sheet filed shortly before the 90-day deadline was to expire, has charged the accused Shahabuddin, Baldev Jat and Sohan Lal under Sections 364 (kidnapping or abduction in order to murder) and 120-B (criminal conspiracy) of the Indian Penal Code and various Sections of the Scheduled Castes and Scheduled Tribes (Prevention of Atrocities) Act, 1989.

The investigating agency, which took over the probe into the case in October, has so far questioned several people, including Mr. Malkhan Singh, his brother, his sister and Mr. Maderna's wife Leela Maderna. The CBI investigators are also probing whether Ms. Devi was trying to blackmail Mr. Maderna by threatening to make their relationship public.

Forensic experts making investigations recovered some blood-stained clothes, hair and a locket from a jeep belonging to Shahabuddin two days ago and are treating them as crucial pieces of evidence. Mr. Maderna was called for another session of interrogation on Friday before his arrest in the light of fresh evidence coming in.

The CBI has also doubled the reward, from Rs.5 lakh to Rs.10 lakh, for anyone providing credible information about the missing auxiliary nurse midwife.